1. Field of the Invention
The present invention relates to high speed thermal printers, operable either as a direct thermal printer or a thermal transfer printer, which are configured to operate in rigorous environments, and to provide easy access to the internal structure.
2. Description of the Related Art
There are two basic types of thermal printers, one being direct thermal printers and the other being thermal transfer printers. In thermal transfer printers heat from a thermal head is transferred to an ink ribbon which then applies the appropriate dot to standard paper. By contrast, in direct thermal printers heat from the thermal head is directly transferred to thermal sensitive paper which then forms the appropriate dot.
Thermal printers are generally equipped with a thermal head which includes a plurality of heating elements arranged in a horizontal column, a platen roller and associated drive mechanisms for feeding paper from a paper drive roller. If the thermal printer being utilized is of the thermal transfer type, an ink ribbon and its associated drive mechanisms will be included in the thermal printer. One common characteristic of known thermal printers is that the thermal head is buried within the interior of the printer, which traps heat within the printer. As a result, it is necessary to vent or dissipate the excess heat from the interior of the printer.
Conventional printers are generally configured to operate in a standard business environment. Such an environment typically requires a frame constructed to minimally support the internal components of the product in a stationary environment. Also, conventional thermal printers generally operate at speeds of 300 lines per minute or less. Operation at such speeds in the above described environment do not require extensive shielding from electrical and/or magnetic fields which exist in the environment.
Therefore, a need exists for a high speed combination direct transfer and thermal transfer printer which is constructed for rugged use, i.e., vibration and mechanical shock tolerant, and which essentially shields radiating electrical and/or magnetic interference.